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Dear Guys,

I apologize ahead of time if this is a totally beginner question, however I had some trouble in my last ADR session that I would like to solve and completely handle.

I receive sometimes random video files which I am somehow supposed to be able to play back and sync audio to for ADR sessions, foley sessions, mixing, etc.

Is there some easy rule of thumb I can use to find out exactly what frame-rate the video is at?

Here is what happened in the last session:

I got a MOV file which I opened in QuickTime to see what framerate it was. It told me "29.97". I set it up as 29.97 in Pro Tools and VVTR and suddenly my streamers and beeps were not working - at all. They just didn't show up.

After restarting 4 times and tearing my hair out because the client was going to be in my studio in 30 minutes, I finally tried setting everything to 29.97 DF. This handled it, though I could not find any sign or anything that would be able to tell me for sure that this was the frame rate - so how am I supposed to know?

How do I find out quickly what frame-rate a video-file is at if there is no time-code burn-in on the file?

Is there a third party program I can use that can tell me this?

Sometimes I get 25 frames, 29.97 DF, etc.

Is there a rule-of-thumb, like TV is ALWAYS 29.97 DF?

Maybe if you could point me in the direction of a basic, basic, basic article or book about digital video and frame rates etc. without all of the nomenclature. That would smoke.

Please help!

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5 Answers

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I know this probably doesn't help with your situation now, but i think we need to be very firm on the clients delivering vision files with burnt in TC. If they don't do it, throw the tape at them and say "Do it again!!!" Or tactfully explain why it's necessary. You may already know this, but i can't resist a vent. Best of luck!

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Thank you! . – Utopia May 21 2010 at 0:16
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Ryan, this came in handy for me. Audio Post Production for Television and Film

There is a whole chapter devoted to synchronization which also covers frame rates.

As far as I know there is no rule-of-thumb for this. I thought knowing frame rates for PAL and NTSC would be enough but today with all these new web codecs and different formats, its almost impossible to generalize.

For my projects, I "make sure" I ask about the frame rate. Believe me that's easier than any software or method. I request the contact information of the After Effects compositor, camera-man, etc. from the director so that there is always someone else to confirm.

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Thanks! I think I'll start doing the same. I didn't want to be "intrusive" to the production companies but maybe they'll be glad I care enough about their project to ask. – Utopia May 21 2010 at 0:15
Exactly Ryan, it is better to be considered "intrusive" rather than "the sound guy has no idea about frame rates whatsoever" – Selcuk Can Guven May 21 2010 at 7:52
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This is a perennial issue, because it relies on that most fragile of workflows: Human communication. I've got a background in video and motion graphics, so I've been b*$&*-slapped into being really anal about specs.

My list of vital stats I won't start work (aural or visual) without is: frame rate (to 2 decimals, not integer "shorthand"), drop vs. non-drop (most of my gigs have been NDF, unlike Ian), actual frame size (in pixels), pixel aspect ratio (1.00 or 0.9), and interleaved vs. progressive (eg, 1080i vs. 1080p), sycn sound or MOS (if the former, # of channels, bit rate, sample rate), whether the footage has been pulled up/down (or needs to be), and of course total running time (TRT) after the 2-pop. That's pretty much the bare minimum I need to get started in confidence. IMHO, you're also entitled to know what device was used to capture the footage, as this can explain potentially odd frame rates.

For what it's worth, anyone with After Effects can open footage and tell you a lot of this stuff, more than one can usually get with most NLE (nonlinear editing) software (correct me via comments if I'm wrong, though).

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Thanks for the answer - pardon me for asking but what is MOS? – Utopia May 20 2010 at 21:06
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 filmsound.org/terminology/mos.htm – Matt Cavanaugh May 20 2010 at 22:49
Ahh. Thank you. – Utopia May 21 2010 at 0:14
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 Yeah, sorry about all the alphabet soup, Ryan! – NoiseJockey May 21 2010 at 15:07
No problem! Funny thing is, I asked the video guys I work with and they knew right away what MOS meant. Go figure. – Utopia May 21 2010 at 21:29
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You absolutely have every right to ask the editor, or whomever is the project manager, to get you all of the information you need. They should know enough to get you sample rate, bit depth, time code info, frame rates, etc. If they don't tell you all of those things and you have to ask them for it you're essentially doing their job for them, or at least part of their job.

Yes, 29.97 is standard for broadcast but who is to say the camera ops and editor know that? They may very well have messed up during shooting or editing and just not admitted it.

I always ask the project manager and/or editor what the frame rate SHOULD be and then I double check it in QT and Nuendo.

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Matthew's post reminds me that there's another key player in the audio post workflow: The telecine/dailies/rushes company. Sometimes half the decisions made around deliverables and formats are for the benefits of the graveyard shift that renders out dailies or rushes, and that can ripple out to all aspects of production and post. Not that you need to contact the telecine house, necessarily, but good to know that this group drives a fair amount of these decisions. FWIW. – NoiseJockey May 21 2010 at 15:09
Thanks Matthew. Your website rocks by the way. – Utopia May 21 2010 at 21:28
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I'd agree with burnt in TC, it's something I always ask for, then there's no problems.

I've obviously heard of 29.97 but have only ever used 29.97DF on any NTSC projects.

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Yeah - most TV stuff is to stay in time with real-time clocks, right? – Utopia May 21 2010 at 0:16
real-time clocks? – ianjpalmer May 21 2010 at 8:08
Doesn't 29.97 DF get used more often for broadcast because with the dropped frame it keeps time better with real time? Like your wristwatch? Rather than 29.97 which will be off 3 seconds or whatever at the end of an hour? – Utopia May 21 2010 at 21:26
A co-worker told me that.. and if I'm totally wrong then you know why I need to read up on it! – Utopia May 21 2010 at 21:30
Yup, you're correct. Sorry, brain was frazzled yesterday and real-time clocks is really rather obvious. en.wikipedia.org/wiki/Drop_frame_timecode - reading that I don't see why 29.97 exists without the DF. My boss did explain it once. Recently we've changed our workflow and all the international projects are done in 24p so I've filed away all his explanations. – ianjpalmer May 22 2010 at 9:00

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